Flipping Daubert: Putting Climate Change Defendants in the Hot Seat

Ryan Hackney

2008 First Place Winner

Can plaintiffs in climate change lawsuits use the Daubert standard to exclude testimony by defense experts? Since the United States Supreme Court announced the standard in Daubert v. Merrell Dow Pharmaceuticals, Inc.,[1] it has been used almost exclusively to the benefit of defendants. There is no theoretical reason, however, why plaintiffs could not use Daubert challenges to exclude testimony by defense witnesses in a scientific field in which the great weight of scientific research supports the plaintiffs’ claims. It is likely that in many cases climate change litigation will present such a situation. An overwhelming body of evidence now supports the conclusions that human activities are increasing atmospheric levels of greenhouse gases (“GHGs”), that these increased levels of GHGs are leading to warming of the atmosphere, and that this warming will have widespread effects on climate.[2] This paper refers to those conclusions and the research behind them as the consensus model. In recent years parties opposed to GHG regulations have attacked the consensus model in the public arena and in the political process with scientific assertions that could probably not withstand a Daubert challenge in the courtroom. This paper examines how such assertions might arise in the litigation process, and considers four ways in which plaintiffs may use the Daubertstandard and the federal rules of evidence to exclude and restrict defense testimony: challenge the witness, challenge the reliability of the evidence, challenge the fit of the evidence to the case, and challenge the conclusions a witness may draw from otherwise admissible evidence.

Part I of this paper examines the field of climate change litigation and considers the kinds of scientific disputes that are likely to arise in future litigation. Part II looks at the Daubert standard and Rule 702 of the Federal Rules of Evidence. Part III applies the Daubert standard to actual cases of “experts” and scientific assertions that prominent climate change skeptics have publicly advanced in the debate over climate change. Part IV considers what conclusions can be drawn from this analysis.

This paper suggests that Daubert will provide an effective tool for climate change plaintiffs. Experts, evidence, and conclusions that climate change skeptics have successfully advanced in the public arena would probably not surviveDaubert scrutiny. An interesting aspect of this conclusion is that much of what has passed for a scientific dialogue in the political arena would not even be admitted into a courtroom. This distinction presents interesting implications for the role that climate change litigation can play in shaping the national debate on climate change. Another interesting implication is that if plaintiffs are successful in using Daubert challenges in climate change litigation, they may help open the door for plaintiffs to use Daubert in other contexts.

Part I: What Scientific Disputes Are Likely to Emerge in Climate Change Litigation?

This paper is based on three premises: first, that plaintiffs will continue to bring climate change lawsuits; second, that some will successfully make it to trial; and third, that a direct conflict over the science of climate change will eventually emerge in the courtroom. Regarding the first premise, much has been written about climate change lawsuits that have been filed and that could theoretically be filed.[3] There are a huge number of obstacles that climate change plaintiffs will need to surpass in order to reach trial, including establishing a duty,[4] and surmounting such jurisdictional bars as standing, preemption, and political question.[5] This paper assumes that some plaintiffs will be able to surpass such obstacles to reach the point where a challenge to scientific evidence will be relevant. If climate change lawsuits reach that stage, it seems inevitable that some will wrestle with the scientific evidence for the biggest climate change questions: Is it happening? What is causing it? What will it mean?

It is interesting that there has not been much direct conflict over the scientific evidence in climate change lawsuits to date. Cases so far have generally been dismissed on jurisdictional grounds or decided on grounds other than the science. The most significant case to date was Massachusetts v. EPA, which was brought by a group of states to compel the EPA to regulate carbon dioxide (“CO2”) as a pollutant under the Clean Air Act (“CAA”).[6] InMassachusetts the science of climate change was never directly disputed in the courtroom because “EPA does not dispute the existence of a causal connection between man-made greenhouse gas emissions and global warming.”[7]The case was litigated, rather, on grounds of standing, interpretation of the Clean Air Act, and the administrative discretion of the EPA. A number of cases involving the National Environmental Policy Act have likewise been decided on grounds of statutory interpretation and compliance rather than on direct examination of scientific evidence.[8]

To date, the few climate change cases brought on common law causes of action have generally been dismissed on jurisdictional grounds. The first climate change lawsuit brought on public nuisance was Connecticut v. American Electric Power Co., which was brought against five public utility companies by the state of Connecticut seeking caps on carbon emissions by the defendants as well as a schedule for future reductions.[9] This case was dismissed as a nonjusticiable political question before any scientific evidence could be presented.[10] In California v. General Motors Corp., a public nuisance claim seeking damages from several automakers on behalf of the people of California, the District Court dismissed the case without prejudice as a nonjusticiable political question before any debate over competing scientific claims could emerge.[11] Because the few climate change cases that have reached courts so far have been decided on grounds of jurisdiction or statutory interpretation, no cases have yet really wrestled with the central scientific questions of climate change. Global warming has not yet had its Scopes Monkey Trial.[12]

Although climate change litigation to date has focused little on the scientific questions of climate change, it seems inevitable that future litigation will focus on such questions. One likely path is in the follow-up to Massachusetts v. EPA. In Massachusetts the court determined that CO2 is a pollutant as defined by the CAA.[13] Although the Court did not specifically command the EPA to regulate CO2, it did state, “EPA can avoid taking further action only if it determines that greenhouse gases do not contribute to climate change or if it provides some reasonable explanation as to why it cannot or will not exercise its discretion to determine whether they do.”[14] With these words, the Court essentially set up the next round of litigation. The EPA can only avoid regulating CO2 if it determines that the gas does not contribute to climate change, in which case the original plaintiffs and probably others besides will take EPA back to court to fight over this scientific determination. If instead the EPA chooses to regulate CO2, the potentially regulated parties who filed amicus briefs in Massachusetts v. EPA will most likely sue the EPA on the grounds that its determination was unreasonable. Either way, the EPA will have to defend its position in court on the basis of scientific evidence.

New challenges on the CAA will almost certainly expand in scope from the focus on new motor vehicle standards inMassachusetts v. EPA. Language similar to that controlling new motor vehicle regulations in CAA §202 – the provision at issue in Massachusetts – also appears in CAA §213(a)(4) regarding non-road engines; thus, the next round of litigation will probably expand to construction equipment as well.[15] Litigation could also arise to make EPA declare CO2 and other GHGs as criteria pollutants for CAA §108, which could result in state-by-state implementation plans like those used to combat ozone.[16] To summarize, litigation concerning the treatment of GHGs by the CAA is almost certain to continue, and that litigation will most likely have to address the scientific questions of climate change. Although Daubert is not strictly applicable to the proceedings of the EPA, the Seventh Circuit has ruled that the spirit of Daubert applies to administrative agency proceedings.[17]

It is likely that scientific challenges will also arise in climate change lawsuits based on common law actions, should they ever make it to court. Scholars have argued that climate change plaintiffs may be able to prevail on a wide range of tort theories, such as public and private nuisance, negligence, and product liability.[18] If climate change progresses as predicted by the consensus position, the damages and costs of adaptation will be enormous; the interest in finding parties to pay those costs will be likewise enormous.[19] A wide array of scholars, attorneys, and possible plaintiffs are looking into the viability of common law actions on climate change, and it seems likely that, in the absence of express legislative preemption, some of them will make it to court. This paper assumes that this will happen.

For the purposes of this paper, I will consider a hypothetical common law lawsuit between a generic plaintiff – e.g. a coastal community seeking damages for their lost coastline from rising seas, a mountain community seeking damages for their lost water supply from diminished snowfall, or an Inuit community seeking damages for a lost way of life from an altered Arctic ecosystem – and a generic defendant – e.g. a utility company or an automobile manufacturer. This paper asks what evidence that defendant might present in order to establish that its actions contributing to GHG emissions – e.g., constructing a new coal-burning power plant or manufacturing and marketing a nine-mile-per-gallon SUV – are reasonable. I choose the standard of “reasonable” because this concept is central to the common law actions available to climate change plaintiffs. For example, a public nuisance is “a substantial and unreasonableinterference with a right held in common by the general public, in use of public facilities, in health, safety, and convenience.”[20] Plaintiffs seeking recovery under a products liability theory of defective design must show that “the foreseeable risks of harm posed by the product could have been reduced or avoided by the adoption of areasonable alternative design . . . and the omission of the alternative design render[ed] the product not reasonablysafe.”[21]

Determining whether the defendant’s actions were reasonable or unreasonable will be key to determining liability in common law actions, and this consideration is also relevant in disputes over regulatory actions. A court can find that an agency abused its discretion if, in the absence of clear statutory language, its actions were “arbitrary and capricious.”[22] While this standard is not precisely the same as reasonability, the same sorts of evidence and arguments will be advanced to prove or disprove either standard. The concept of reasonability will also loom large outside of the courtroom. Climate change lawsuits are taking place as part of a larger social and political debate over what to do about global warming, and for purposes of public relations and politics both plaintiffs and defendants will want their side to appear more reasonable.

To make this exercise realistic, I only consider actual claims that have been publicly put forth by prominent climate change skeptics. It would be easy to knock down flimsy strawmen with the Daubert hammer, and for this reason it would be pointless to do so. The parties that are likely to be defendants in climate change lawsuits will be sophisticated litigants, and they will know better than to present obviously “junky” science to the fact-finder. Climate change skeptics have publicly put forth a wide range of scientific claims that could be relevant to the question of whether our hypothetical defendant’s actions are reasonable. The scientific claims of climate change skeptics generally take one of three approaches: (1) global warming is not happening; or, (2) if it is, it is not caused by humans; or (3) if it is, that is a good thing.[23] Any of these three conclusions could make the defendants’ actions appear reasonable. I examine some of these claims in Part III; I have attempted to choose scientific claims that accurately and fairly represent the skeptics’ position.

Part II: Daubert and the Federal Rule of Evidence 702 – Judges as Gatekeepers

The Supreme Court advanced the Daubert standard in 1993 as a response to widespread dissatisfaction with the previous Frye standard for admissibility of scientific expert testimony.[24] In the 1923 case of Frye v. United States the Supreme Court stated that the test for admissibility of expert testimony is whether it is “sufficiently established to have gained general acceptance in the particular field in which it belongs.”[25] This “general acceptance” test was the prevailing standard for admissibility of expert testimony in federal courts until the adoption in 1975 of the Federal Rules of Evidence, which stated in Rule 702 that expert testimony regarding scientific and technical matters should be admitted if it will “assist the trier of fact,”[26] and stated in Rule 703 that an expert may rely upon facts and data “reasonably relied upon by experts” in the field.[27] Although courts initially assumed that the Federal Rules of Evidence implicitly adopted the Frye test, judges and commentators soon began to argue that the Rules of Evidence might provide a test that differed from and superseded the Frye test.[28] The Supreme Court took up this question inDaubert in 1993, and determined that the Federal Rules of Evidence created a new standard of admissibility for scientific evidence that superseded the “general acceptance” test.

In Daubert the Supreme Court interpreted Rule 702 to mean that trial judges should subject expert testimony to a two-prong analysis.[29] First, is the scientific methodology underlying the testimony reliable — is it “ground[ed] in the methods and procedures of science” and “supported by appropriate validation.”[30] The Court provided a series of factors that courts may consider in determining whether a methodology is reliable:

(1) Testability: “whether it [the theory or technique] can be (and has been) tested”;[31]

(2) Peer review: “whether the theory or technique has been subjected to peer review and publication”;[32]

(3) Error rate: “the court ordinarily should consider the known or potential rate of error”;[33]

(4) Control standards: “the court should consider . . . the existence and maintenance of standards controlling the technique’s operation”;[34]

(5) General acceptance: “Widespread acceptance can be an important factor in ruling particular evidence admissible.”[35]

The Court emphasized that “[t]he inquiry envisioned by Rule 702 . . . is a flexible one,” and thus compliance or noncompliance with any of the listed factors is not necessarily determinative of admissibility.[36] The second prong ofDaubert is whether the testimony is relevant to the questions at hand — does it “assist the trier of fact to understand the evidence or to determine a fact in issue.”[37] The Court described this prong as a question of “fit,” and gave an example of testimony about the phases of the moon; such testimony might be relevant if darkness is an issue in the case, but not if the issue is whether an individual was unusually likely to behave irrationally on a given night.[38]

In replacing a well-established, if unsatisfactory, test with a new multi-factor test dealing with issues with which many judges were unfamiliar, Daubert unleashed a torrent of questions about which types of expert testimony would be admissible under the new standard. The Supreme Court offered some clarity in subsequent decisions. In General Electric Co. v. Joiner the Court made two important clarifications.[39] First, the Court noted that federal district judges had wide discretion in determining whether expert testimony met the Daubert standard, and that their determinations would be subject only to a permissive “abuse of discretion” standard of review.[40] Second, the Court stated that judges were free to consider the validity of the conclusions experts drew from otherwise reliable data, and could exclude testimony when “there is simply too great an analytical gap between the data and the opinion proffered.”[41]In Kumho Tire v. Carmichael the Court stated that the Daubert standard applies to admissibility of all expert testimony, not just testimony on scientific or technical matters.[42] The Court also reaffirmed that the Daubert inquiry is flexible, and that trial courts have wide latitude in how to apply the factors.[43]

In 2000 the Supreme Court approved amendments to the Federal Rules of Evidence that brought the rules governing expert testimony in line with the Daubert standard.[44] In addition to minor changes to Rules 701 and 703, the amendments to 702 incorporated the Daubert emphasis on the reliability of scientific methodology. Rule 702 now reads:

If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based on sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.[45]

The advisory committee to the 2000 amendments voiced support for the five reliability factors listed in Daubert, and also pointed to five other factors that courts could consider in evaluating the reliability of an expert’s scientific testimony:

(1) Whether experts are “proposing to testify about matters growing naturally and directly out of research they have conducted independent of the litigation, or whether they have developed their opinions expressly for purposes of testifying.”

(2) Whether the expert has unjustifiably extrapolated from an accepted premise to an unfounded conclusion.

(4) Whether the expert “is being as careful as he would be in his regular professional work outside his paid litigation consulting.”

(5) Whether the field of expertise claimed by the expert is known to reach reliable results for the type of opinion the expert would give.[46]

The combination of Daubert and its progeny with the Rule 702 amendment committee notes means that a district court judge has great discretion in determining whether to admit or deny expert testimony.

While Daubert dealt specifically with Rule 702, other rules can also be important in challenging expert testimony. Probably the most important of these is Rule 403, which applies with as much force to expert opinion testimony as it does to any other evidence.[47] Rule 403, labeled “Exclusion of Relevant Evidence on Grounds of Prejudice, Confusion, or Waste of Time,” states:

Although relevant, evidence may be excluded if its probative value is substantially outweighed by the dangers of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.[48]

Rule 403 has a broad reach; evidence that may be otherwise relevant and admissible may be excluded if its probative value is outweighed by the danger of unfair prejudice and confusion. In a Daubert challenge, it provides a further means of excluding expert testimony that might pass Daubert‘s relevance and reliability requirements.

Other federal rules that are relevant to Daubert challenges are Federal Rules of Civil Procedure 26(a)(2)(B) and 26(e)(1), which require an expert witness to submit an expert report describing all of the opinions about which he or she will testify,[49] and Federal Rule of Civil Procedure 37(c)(1), which provides for the exclusion of expert testimony that has not been described in the expert report.[50] In the context of a Daubert challenge, the expert report required by Rule 26 will most likely provide the basis for the challenge, and Rule 37 provides litigators with a means of excluding evidence that was not considered in the challenge. While these rules are tangential to the central focus of the paper, they provide part of the procedural backdrop through which a litigator can use Daubert.

The outcome of any Daubert challenge is hard to predict.[51] Trial judges have broad discretion in applying a number of rules and factors, and scientific testimony on complex subjects is, by its nature, often hard to predict. While the effect of any given Daubert challenge may be difficult to predict, one trend is clear: Daubert challenges are far more likely to result in the exclusion of a plaintiff’s proffered testimony than that proffered by a defendant.[52]

Professor D. Michael Risinger studied the effects of Daubert challenges in hundreds of federal civil cases between 1993 and 2000 and concluding that around 90 percent of reported Daubert challenges are brought by defendants, with around two-thirds of those challenges successfully excluding the plaintiff’s expert testimony, whereas in the small number of cases in which a plaintiff challenged a defense expert the challenge was successful less than half of the time.[53] One study by the RAND Institute for Civil Justice found in 2002 that the percentage of federal civil cases resulting in summary judgment doubled after Daubert, and that over 90 percent of summary judgments involvingDaubert challenges were decided against the plaintiff.[54] One explanation for this trend is that plaintiffs are naturally more susceptible to Daubert challenges because they bear the burden of proof, and are therefore in the position first to present scientific evidence that can be challenged. This factor can present a substantial obstacle in scientifically complex areas such as environmental or toxic tort cases, particularly where the plaintiff relies on novel scientific theories or evidence.[55] Another obstacle for plaintiffs is that the reliability standards outlined in Daubert can require substantial resources to meet, even where claims are strong, and thus Daubert often favors the party with the greater resources, which usually means the defendant.[56] It has also been suggested that scientists and medical professionals have grown more reluctant to testify for plaintiffs since Daubert over concerns that their scientific qualifications and methods will be challenged in court.[57]

Although Daubert challenges have generally worked to the benefit of defendants, some plaintiffs have been able to challenge defense experts effectively. In Edwards v. Safety-Kleen Corp., a case involving challenges to both plaintiff and defense experts, the court found that an oncologist’s testimony for the defense was unreliable because his assertion that a worker could not have had benzene-induced leukemia because he did not exhibit certain chromosomal aberrations relied on an untested theory that was supported neither by peer-reviewed publications nor by general acceptance in the field of oncology.[58] Another example is Harris v. General Motors Corp., in which the Sixth Circuit overruled a summary judgment for a defendant on the grounds that the summary judgment relied on insufficient scientific testimony.[59] Although the plaintiff in Harris had not raised a Daubert challenge at the trial level, the appeals court ordered the trial court to conduct a Daubert hearing on the defendant’s evidence on remand, and suggested that the testimony of one of the experts might fail Daubert‘s reliability component.[60] And in Cook v. American S.S. Co., the Sixth Circuit ruled that a defense expert’s testimony should not have been admitted at trial because the expert had not performed any scientific tests on a rope that he concluded, on visual inspection alone, had been damaged by burning.[61]

Thus, while Daubert challenges have primarily worked to the benefit of defendants, there is no reason why plaintiffs cannot use them in areas in which the plaintiff’s position is supported by the weight of the scientific evidence.[62] As we shall see, climate change litigation appears to be such an area.

Part III: How Climate Change Plaintiffs Can Use Daubert to Exclude Defense Expert Testimony

1. Challenging the witness – Can a weatherman predict the climate?

The most direct way to exclude a witness’s testimony is to exclude the witness himself. In order to testify as an expert, a witness must qualify for the status of expert by means of “knowledge, skill, experience, training, or education.”[63] If in the eyes of the trial judge the proposed expert fails to meet this qualification, the judge can exclude the witness’s testimony.[64] This facet of Rule 702 may be particularly relevant in a field in which many “experts” have been put forth in the public arena who lack substantial expertise in climatology.

Senator James Inhofe of Oklahoma, a former chair and current member of the Senate’s Environment and Public Works Committee (“EPW”), issued a Senate report on December 7, 2007 that claimed, “Over 400 Prominent Scientists Disputed Man-Made Global Warming Claims in 2007.”[65] Inhofe, who stated on the Senate floor in 2003 that global warming may be “the greatest hoax ever perpetrated on the American people,”[66] has been one of the most prominent opponents in Congress of any GHG emissions regulations. Inhofe pointed to the “400 Prominent Scientists” as evidence that there could not be a consensus on climate change as reported in the IPCC 2007 report. Some critics have suggested that Inhofe’s report misrepresents the views of some of the 400 prominent scientists, and that a large percentage of them are neither prominent nor scientists.[67]

One of the report’s listed “prominent scientists,” Chris Allen, is a television weatherman for the Kentucky Fox affiliate WBKO. Chris Allen was also cited as an authority in an earlier press release from the EPW Committee.[68] The EPW website notes that, “Allen has the Seal of Approval of the National Weather Association and is the chairman of the Kentucky Weather Preparedness Committee.”[69] The website goes on to quote Allen as saying “As I have stated before, not only do I believe global climate change exists – it has always existed. There have been times of global warming and cooling.”[70] The website provides a link to Allen’s blog on WBKO’s website, in which he explains his view that recent observations of rising world temperatures are explained entirely by natural cycles, and that theories of anthropogenic global warming are implausible.[71] Allen’s blog also discloses that he does not have a college degree, that he is mostly self-taught in meteorology, and that his main argument against anthropogenic global warming is that God would not allow it.[72]

Could the defendant in our hypothetical climate change lawsuit, possibly taking the advice of Senator Inhofe, present Allen as an expert in the courtroom to debunk claims of anthropogenic global warming? Inhofe apparently believes that Allen is sufficiently authoritative to present as a climate expert in press releases and on the website for the EPW Committee. A senator’s website, however, is not governed by the Federal Rules of Evidence. It is likely that Allen would not withstand a Daubert challenge as an expert witness.

A trial judge has a great deal of discretion in weighing a proffered expert’s “knowledge, skill, experience, training, or education.”[73] In this analysis, Allen’s lack of an advanced degree is not in itself dispositive. A witness without formal education may still qualify as a witness on the basis of experience or independent study,[74] and the seal of approval of a national organization can be indicative of expertise.[75] On the basis of these factors, Allen would probably qualify as an expert on local weather forecasting. But weather and climate are not the same thing.[76] While weather forecasts rarely look forward past two weeks, climate forecasts consider a timespan of centuries. While weather forecasts tend to be local or at most regional in focus, climate considers the world as a whole. Climate also considers a range of disciplines – atmospheric chemistry, oceanography, ecology, physics – that only tangentially come into play in meteorology as practiced by local weather forecasters. Considering this distinction, the trial judge will have to determine whether Allen’s tangential knowledge of climatology can assist the trier of fact.[77] A judge may exclude a witness if it is determined that the witness’s expertise is not relevant to the questions at hand.[78] Our hypothetical plaintiff could make a compelling argument that expertise in the field of weather forecasting does not make a witness competent to provide expert testimony on the question of whether GHG-induced climate change is occurring or will occur. In this case it is likely that what counts as an expert in the political process will not cut it in the courtroom.

A more striking example of the disconnect between standards of expertise in the courtroom and in the public arena is the acceptance of the novelist Michael Crichton as an expert by many global warming skeptics. Crichton’s status in this field derives mostly from his 2004 science fiction novel State of Fear, in which environmental terrorists stage fraudulent disasters in order to help their fundraising, and the novel’s hero spends much of the book debunking global warming.[79] Many of Crichton’s scientific assertions in the novel have been challenged.[80] In 2005 Senator James Inhofe invited Crichton to speak to the Senate EPW Committee on the issue of climate change, and stated in his introduction that he had made State of Fear required reading for the members of the committee.[81] President Bush later invited Crichton to the White House to share his views on climate change.[82] Crichton has given speeches on the subject to groups such as the American Enterprise Institute and the Brookings Institution.[83] Clearly, Crichton is more than willing to express his views on climate change, and a senator and the president of the United States are willing to look to him as an expert. But could he testify about climate change in a courtroom?

It is likely that Crichton would not qualify as an expert on the subject of climate change. While Crichton does have a degree from Harvard Medical School, he does not have any formal training in a climate-related field, nor has he ever worked in the field aside from his research for State of Fear.[84] Crichton’s medical degree and years of writing about scientific subjects might make him competent to testify about science in a general way, but they do not make him competent to testify about any scientific specialty.[85] Crichton’s research on climate change prior to writing the book could theoretically make him an expert on the subject,[86] but the question for the judge would be whether a person with medical training who has spent a few years independently reviewing the science and policies surrounding climate change is really enough of an expert to assist the trier of fact in understanding the complicated subject matter. Our plaintiff could make a good argument that Crichton lacks sufficient training in the more rigorous scientific disciplines of climate change to form expert opinions on the science, and that he is in effect nothing more than an educated layman on the subject of climate change. This argument could be strengthened by the fact that Crichton conducted his research in order to flesh out a novel about murderous eco-terrorists; one could infer that his research may have been less about the disinterested search for the truth than about gathering material for the story he wanted to tell. The plaintiff could further argue that Crichton’s testimony, due to his stature as a public figure, would have a prejudicial effect disproportionate to any probative value it would provide.[87] There is a good chance that a judge would disqualify him as an expert.

Challenging a proposed witness’s qualifications could be an effective tactic for climate change plaintiffs. As the above examples illustrate, prominent skeptics such as Senator Inhofe have frequently relied on the authority of individuals, such as Allen and Crichton, who would probably not withstand Daubert challenges as expert witnesses. One reason for this phenomenon is that as the evidence for global warming has increased the number of practicing climatologists that doubt the consensus model has dwindled. There are still a significant number of legitimate scientists, however, that are skeptical of the climate change model and would most likely qualify as experts on the subject.

Sitting next to Crichton at Inhofe’s Senate Committee hearing was another meteorologist who would most likely fare better than Allen in an expert witness challenge. Bill Gray, a Professor Emeritus in atmospheric science at Colorado State University, spoke out against the “bogus science and media hype” that he feels is behind the standard theory of anthropogenic global warming.[88] Gray stated at the hearing that any measured warming in recent decades has been due to natural changes in the thermohaline circulation of the ocean, and that this same natural cycle will lead to global cooling within the present decade.[89] Inhofe and other opponents of GHG regulations have enthusiastically embraced Gray’s theories, in part because, unlike Allen and Crichton, Gray is a practicing scientist with a Ph.D in Geophysical Sciences and a list of peer-reviewed scientific publications spanning more than four decades.[90] Gray was one of the pioneers of the seasonal forecasting of hurricanes, and has been recognized for decades as one of the most influential teachers and accurate forecasters in the study of hurricanes.[91] Although his specialty is not climatology, he has training in and experience with many of the sub-disciplines and quantitative methods employed by climatologists. He is unquestionably an expert in large-scale weather systems, and in recent years he has increasingly focused on the issues of climate change. In sum, he has knowledge, skill, experience, training, and education in fields highly relevant to climate change issues. There would be little point in arguing that Gray is not an expert for the purposes of Rule 702. To challenge Gray effectively, an attorney would need to dig deeper into the Daubert standard and look to the reliability of his theories and techniques.

2. Challenging Reliability: How many peers does it take to review a paper?

A judge will almost certainly let Bill Gray testify on certain climate change issues. As one of the nation’s premier experts on hurricane formation, he would certainly be allowed to offer his opinions on the connection between global warming and increased hurricane activity (he believes there isn’t one).[92] A judge would also most likely allow Gray to testify as to areas of uncertainty and possible weaknesses in the consensus model. But not all of Gray’s publicly stated opinions would necessarily pass Daubert scrutiny. His testimony before the Senate committee and other public statements have focused on what he sees as the true cause of perceived global warming – the thermohaline circulation (“THC”).[93] The THC is a circulation pattern of water among the oceans driven by temperature (“thermo”) and salinity (“haline”), which together determine the density of the water.[94] The THC, while widely recognized as a fundamental component of the world’s climate systems, is not very well understood due to the difficulty of measuring a world-wide deep ocean system that operates on an extremely long time scale (it is thought that the circulation takes around 1600 years to complete its circulation of the world’s oceans).[95] Gray has often stated that the THC provides the explanation for recent perceived warming, and also that it will inevitably lead to global cooling in the near future. His skepticism of the consensus model is inextricably linked to his belief that this alternate factor plays a far larger role in controlling climate than do GHG emissions.[96] But can Gray testify about his THC theory in a courtroom?

There is reason to think that Gray’s theory would fail the Daubert test for reliability. As discussed in Part II, the five reliability factors are: testability, peer review, error rate, control standards, and general acceptance.[97] Considering first the factor of testability, as well as the related factors of error rate and control standards, we must note that tests are difficult to conduct when talking about a theory regarding a multi-century circulation pattern through the world’s oceans. Gray’s theory can be tested by seeing how well it conforms with past observations of THC, but the effectiveness of this test is limited by the paucity of such observations. Matching past data is also not very useful for testing the predictive capacity of the theory, particularly given changing atmospheric chemistry, which is really the point of any theory regarding climate change. The only way to test the predictive capacity of the model is to see how it plays out on computer-based global climate models – such as those cited in the IPCC reports – but Gray has repeatedly stated his conviction that computer models are essentially worthless at predicting future climate.[98] In effect, Gray’s theory gets one test – the one we are conducting today by pumping several billion tons of carbon into the atmosphere every year. If the world actually does start to cool within the next decade, that will be evidence supporting Gray’s theory, but that is like running your first test of a possibly toxic substance on a live patient – once you have your answer, it could be too late. There is also no way to assign error rates or control standards to an experiment involving all of the world’s oceans. Since the factors of testability, error rates, and control standards are inherently difficult to apply to a field such as long-term climatological predictions, the inability of Gray’s theory to satisfy these criteria is probably not fatal, but the factors do suggest a general reason to question the reliability of the theory.

Gray’s theory founders badly on the criteria of peer review and general acceptance. Courts have found that lack of support in peer-reviewed publications can be decisive in excluding testimony under Daubert.[99] Although Gray has published widely in the field of atmospheric science, he has never published in a peer-reviewed journal his theory of the role of the THC in controlling climate.[100] It is not clear whether this is because Gray has never submitted this theory for publication or because it has never been accepted. If the explanation is the former, then the obvious question is why not? If a widely-published senior scientist publicly and stridently avows a theory, why would he not seek to publish it in the accepted forums of his field? There is no answer to that question that argues in favor of the theory’s reliability. On the other hand, if no journals have chosen to publish it, again the question is why not? Either the papers failed to meet the journal’s standards – which would argue against a finding of reliability – or, as the community of climate change skeptics would more likely argue, Gray’s papers were rejected because his theory differs from the climate change model that is accepted by the scientific majority that runs these journals. But if that is the case, then Gray’s theory fails the fifth Daubert criterion of general acceptance in its field.[101] It is worth noting that in a study of 928 scientific papers dealing with climate change published in peer-reviewed journals between 1993 and 2003, seventy-five percent of the papers explicitly or implicitly accepted the consensus model while not a single paper explicitly rejected it.[102] While this could be the result of a corrupt bias by the scientific majority, a court has only limited discretion to second guess the unambiguous judgment of the scientific majority. The Daubert factors of peer review and general acceptance recognize that at some level a court has to trust that the majority of scientists know what they are doing.

Not only is Gray’s THC theory not widely accepted in the field, it relies on premises that likewise lack general support. A principal component of his theory is that the THC primarily upwells in the tropics, but recent studies have suggested that upwelling in the tropics is independent from the THC.[103] Gray’s theory also rejects a positive feedback loop between CO2 and water vapor that will lead to increased atmospheric warming, but this positive feedback loop has been included in climate models by most climatologists for decades, and has been supported by direct observational data.[104] Points such as these give the plaintiff ammunition for attacking the theory’s reliability. The plaintiff could make a strong argument that Gray’s theory does not pass any of the five reliability factors articulated in Daubert. The likely effect of a Daubert challenge would be that Gray might be permitted to testify generally about hurricane formation, but he would not be able to present his theory about the connection between THC and climate to the fact-finder.

Daubert reliability challenges may be an effective tool for plaintiffs to use to restrict the testimony of scientists who, like Gray, clearly are experts in their field, but subscribe to theories outside of the climatological mainstream. This is relevant to climate change litigation, because the relatively small number of practicing climatologists that challenge the consensus model generally adhere to alternative theories that are, almost inescapably, not generally accepted in the field. While the Daubert standard is in theory more forgiving of unorthodox theories than was the old Frye test, it still retains the Frye criterion of widespread acceptance, and thus experts who wish to testify against the consensus model are walking in the door with a strike already against them. As Gray’s example shows, challenging the reliability of such an expert’s theories will be relatively straightforward if the expert has not published the theory in a peer-reviewed journal. This could apply to the work of quite a few climate change skeptics, as much of the research that has challenged the consensus model in recent years has been published not by peer-reviewed journals but by conservative “think tanks” with no reputation for scientific credibility.[105] But will a reliability challenge work if a proffered expert has published his theories in a peer-reviewed journal?

Sherwood Idso would make a good test case of such an expert. Idso, who has served as a research physicist with the U.S. Department of Agriculture and as an adjunct professor in Geology and Botany at Arizona State University, is the president of the Center for the Study of Carbon Dioxide and Global Change, an organization that promotes the view that heightened CO2 levels are a good thing because of their beneficial effects on plant growth.[106] It should be noted that the Center for the Study of Carbon Dioxide and Global Change has been accused of receiving funding from ExxonMobil,[107] and that in 1991 Idso produced a video for the Western Fuels Association, a coal industry association, which extols the agricultural benefits of heightened CO2.[108] While Idso’s connections to energy interests have led some to question his work as biased, his research on the effects of CO2 on plant growth has been published several times in peer-reviewed journals. His research on the effects of heightened CO2 in boosting growth in Eldarica pine trees, for example, was published in the Journal of Experimental Botany, which is published by Oxford University Press.[109] He published peer-reviewed papers in 2001 and 2004 on the long-term effects of CO2 on growth of sour orange trees.[110] Since Idso is a published scientist who has publicly promoted the benefits of CO2 and has shown a willingness to accept money from energy companies, it is not unthinkable that climate change defendants could turn to him for expert testimony about his research. But would he be allowed to testify?

It is likely that Idso would pass a Daubert reliability challenge. First, there is little question that Idso would qualify as an expert in some aspects of climate change; he is a published scientist who has worked specifically with the biological effects of heightened CO2. Idso’s acceptance of energy company money is irrelevant to this question, as no part of Rule 702 or Daubert suggests that corporate funding diminishes an expert’s qualifications or the reliability of his or her work. While some might argue that this is a blind spot in Daubert,[111] it would probably be unreasonable to institute a rule that prohibits scientists from testifying on behalf of their employees or sponsors. The committee notes to the Rule 702 amendments do allow judges to consider whether an expert is “proposing to testify about matters growing naturally and directly out of research they have conducted independent of the litigation, or whether they have developed their opinions expressly for purposes of testifying,” but this analysis would almost certainly weigh in favor of admitting Idso’s testimony, since the research was conducted years prior to the litigation.[112] And even if Idso is a paid shill of the energy industry in some aspects of his career, he has also published several papers in independent, peer-reviewed journals. To the extent that Idso’s testimony is based on the results of his peer-reviewed studies and other similar publications, it would be difficult to challenge his testimony on the Daubert five-factor reliability test. Testability can be established because the publications describe the tests that Idso conducted to advance his theories. The fact that the papers were accepted for publication in respected journals suggests that the methodology of the test – including error rate and control standards – were sufficiently rigorous that other scientists would accept them as reliable enough for publication. While all of Idso’s conclusions may not be widespread in the scientific community, it is generally accepted among ecologists that heightened CO2 can promote plant growth.[113] If Idso sticks to the information contained in the peer-reviewed publications, a Daubert challenge to his reliability would probably fail.

Am I suggesting that our industrious plaintiff should sit back and allow a paid shill of the energy industry to testify that climate change is good because plants love CO2? Not at all. The plaintiff should argue that Idso’s testimony is irrelevant, and can in no way assist the trier of fact.

3. Challenging Relevance: Plants may love CO2, but so what?

The key question for Daubert‘s relevance test is whether the testimony “will assist the trier of fact to understand the evidence or to determine a fact in issue.”[114] The Supreme Court has stated, “Rule 702’s ‘helpfulness’ standard requires a valid scientific connection to the pertinent inquiry as a precondition to admissibility.”[115] The Court also described this connection as “fit.”[116] The Sixth Circuit interpreted “fit” to mean that “there must be a connection between the scientific research or test result being offered and the disputed factual issues in the case in which the expert will testify.”[117] The Ninth Circuit in the Daubert remand interpreted “fit” to mean that the testimony “logically advances a material aspect of the proposing party’s case,”[118] and stated that federal judges must exclude proffered scientific evidence “unless they are convinced that it speaks clearly and directly to an issue in dispute in the case, and that it will not mislead the jury.”[119]

Will Idso’s testimony about his research on the effects of heightened CO2 on plant growth assist the trier of fact? Obviously, the answer depends on what facts the evidence is supposed to help them determine. Idso’s testimony might fit the case if future agricultural production is an issue in dispute; one could imagine this issue coming up if the plaintiff were an agricultural producer or a community that was suing for potential future crop losses due to drought or storms brought on, in part, by the defendant’s contribution to climate change (although if drought made farming impossible then any beneficial effects of heightened CO2 would be beside the point). More likely, however, agricultural losses will be at most a tangential issue to the plaintiff’s claims. If, for example, the plaintiff is an Inuit community claiming that the defendant’s unreasonably inefficient automobiles contributed to the loss of the community’s village and way of life through rising sea levels and loss of sea ice, how is it relevant that a farmer unrelated to either side might theoretically benefit? The same question would apply to plaintiffs seeking damages for loss of coastal property, loss of freshwater supply from melting glaciers, loss of ski business from a shortened winter season, and a wide variety of other foreseeable claims. In all of these cases, the plaintiff should point out that future agricultural productivity is not at issue in the case.

The defendant should argue that Idso’s testimony is relevant, even if agricultural productivity is not explicitly at issue in the case, because it demonstrates the reasonability of the defendant’s actions by establishing a benefit of higher CO2 emissions – increased agricultural production – to weigh against the negative aspects of CO2 emissions. The plaintiff should respond that theoretical benefits to unrelated third parties are simply irrelevant to determining whether the defendant’s actions were reasonable. For climate change defendants to argue that their actions are justified because of possible benefits to future farmers is somewhat akin to tobacco companies arguing that the benefits of their tax dollars and charitable giving should be taken into account in the risk-benefit analysis of their products; courts have excluded such testimony as irrelevant.[120] The plaintiff should further argue that any agricultural benefits, if they exist, do not make the defendant’s actions more reasonable because it is implausible that the defendant chose its course of action because of possible long-term agricultural benefits – no one would reasonably design a car to be inefficient so that plants will grow faster.

If the judge were to determine that theoretical agricultural benefits are at issue in the case, the plaintiff should argue that Idso’s testimony is still irrelevant because his research does not establish that CO2 emissions will actually result in agricultural benefits, but his testimony could confuse the fact-finder into thinking that it does.[121] The Ninth Circuit in the Daubert remand refused to allow the plaintiffs’ experts to testify because their evidence, while suggesting that Bendectin might cause birth defects, could not prove that it causes birth defects.[122] The Ninth Circuit disallowed the testimony out of fear that it could mislead the jury; that same risk is present with Idso’s testimony. Opponents of GHG regulations have for many years promoted the idea that heightened CO2 and climate change in general will be beneficial for agriculture, because the storyline seems to make sense.[123] Plants use CO2 in photosynthesis and many plants grow better in warmer weather, so it makes sense that higher CO2 and higher temperatures could have some kind of fertilizer effect. But do Idso’s studies actually show that climate change will benefit agriculture? The connection is more tenuous than it might at first appear. What Idso’s studies demonstrate is that certain plants accumulate biomass faster under the conditions in which he conducted the studies. There are a number of issues here for the plaintiff to probe.

First, are the effects on the tested plant species similar to what will happen to the thousands of other plant species used in agriculture, and the hundreds of thousands of plants in different ecosystems?[124] In the Daubert remand, the Ninth Circuit ruled that evidence of the drug Bendectin’s teratogenic effect on animals was not relevant to a case involving humans because the extrapolation of that data from animals to humans had not been established as valid.[125] On the same grounds, evidence about the effects of CO2 on Eldarica pines may be irrelevant to the effects of CO2 on a tropical crop like manioc, or a nitrogen-fixing plant like clover. Second, is faster accumulation of biomass always a good thing? Some studies have suggested that plants grown in higher CO2 may have a lower nutritional value due to their faster growth, resulting in malnutrition among insects that feed on such plants.[126] Also, could faster-growing plants lead to faster depletion of soil nutrients? Plant growth is a complicated thing; as any gardener knows, it takes a lot more than air, sunlight, and water to make plants grow.[127] You need soil rich in a variety of minerals, such as magnesium, phosphorus, potassium, and, most importantly, nitrogen.[128] Fostering an environment in which crops exhaust soil nutrients faster than natural cycles can replace them could lead to severe problems in areas in which artificial fertilizers are unavailable or prohibitively expensive. Studies have shown that artificial fertilization can lead to loss of plant species diversity,[129] that climate change can alter species composition in local areas,[130]and that climate change can lead to changes in the timing of plant reproduction.[131] Other studies suggest that long-term exposure to heightened CO2 results in diminishing benefits over time due to changes in the plant’s photosynthetic processes.[132] Idso’s own research supports this finding of diminishing returns.[133]

The point of all this is that plant ecology is complicated, and the long-term response of plants to heightened CO2 will likewise be complicated. While Idso’s studies provide a reason to think that heightened CO2 might benefit agriculture, it would not be scientifically valid to say that the studies establish that heightened CO2 will benefit agriculture, or even that such benefits are more likely than not. The connection between the data and the intended conclusion is too tenuous, although a fact-finder, uneducated in the complexity of plant ecology, could be misled into finding Idso’s results conclusive on the question of agricultural benefits. The plaintiff has a strong argument that, even if the negative consequences of climate change are taken out of the agricultural benefits equation, Idso’s testimony should be excluded under Rule 403 because its probative value is exceeded by its potential to mislead the jury. If the probable negative consequences of heightened CO2 are taken into account, the plaintiff’s argument becomes much stronger.

The projected negative impacts of climate change will almost certainly have damaging effects on agricultural production. Studies have suggested that drought resulting from climate change may cancel out the growth-enhancing aspects of heightened CO2.[134] The consensus model suggests that rising GHGs will result in substantial disruption of ecosystems worldwide, altering temperature and rainfall patterns and contracting coastlines.[135] While it is uncertain whether these effects will harm or benefit agriculture in general, the fact that human agricultural production is currently adapted to world climate as it exists today suggests that changing the climate will at a minimum demand costly adaptations, and could ultimately result in decreased agricultural production (to say nothing of the probably harmful effects on nonagricultural ecosystems such as wetlands, rainforests, etc.). The point is that Idso’s testimony would touch on a small part of a very large and complicated picture. Because the storyline of CO2 as fertilizer has an intuitive appeal, a fact-finder could easily attribute far more significance to the testimony than it merits on scientific grounds. In other words, the testimony has little probative value, but a high chance of prejudicial value. The plaintiff should argue that the testimony fails both Rule 403 and the relevance prong of Daubert.

Thus, our plaintiff can make a strong argument that Idso’s studies on plant growth are irrelevant to the question of whether the defendant’s actions to increase GHG emissions were reasonable. While a plaintiff can make a strong argument on relevance when testimony relates to a tangential issue such as the possible agricultural benefits of heightened CO2, what argument can she make when testimony appears to confront directly the consensus model?

Take, for example, the problem of the melting glaciers. One of the most frequently invoked dangers of global warming is the potential to melt glaciers around the world, reducing supplies of freshwater in many areas and leading to increases in sea level that swamp coastal areas.[136] Observations of retreating glaciers have been some of the most notable direct confirmations of a currently warming atmosphere.[137] The problem of the melting glaciers is one of the most understandable effects of climate change for the general public, so it has received a large amount of coverage in the press. Climate change skeptics have a very direct response to the glacier problem, however. How can the glaciers really be shrinking if we know that glaciers in parts of Greenland and Antarctica are actually getting thicker?

This assertion is not based on junk science. A report published in Science in 2005 by an international team of researchers headed by Ola Johannessen concluded after analyzing satellite data from 1993 to 2003 that the ice sheet in the interior of Greenland had increased in height during that period.[138] Another study published in Science in 2005 by a team led by Curt Davis concluded from analysis of similar satellite studies over Antarctica that the interior ice-sheet in East Antarctica had also thickened between 1992 and 2003.[139] Not surprisingly, climate change skeptics embraced these studies as evidence that the consensus model must be wrong. The Competitive Enterprise Institute, a conservative think-tank that has received a large amount of funding from energy companies,[140] produced a television commercial featuring these two studies that aired in fourteen American cities in May 2006.[141] The commercial stated, “You’ve seen those headlines about global warming. The glaciers are melting. We’re doomed! That’s what several studies supposedly found. But other scientific studies found exactly the opposite. Greenland’s glaciers are growing, not melting. The Antarctic ice sheet is getting thicker, not thinner.”[142] This storyline has a visceral appeal – if some glaciers are melting but others are growing, what are we worrying about? Crichton and Inhofe have both pointed to evidence of expanding glaciers to “debunk” climate change.[143] The skeptic pop-treatise The Politically Incorrect Guide to Global Warming devotes a chapter to the expanding glacier story.[144]

It would be difficult for a plaintiff to exclude the Johannessen and Davis studies under Daubert. In terms of reliability,Science is one of the most prestigious scientific journals in the world.[145] Publication by Science is a stamp of approval by the editors that the research methods relied on in the paper were scientifically sound. In terms of relevance, if the occurrence of global warming is a relevant issue in the trial, it is hard to suggest that evidence apparently contradicting the consensus model is not relevant to the inquiry. And since the rise in sea levels resulting from the melting of the Greenland and Antarctic ice sheets is routinely listed as one of the worst-case scenarios of future climate change, evidence that that melting will not occur is surely relevant. Is our plaintiff doomed to fight this damning evidence in cross-examination?

The answer is yes and no. The plaintiff will probably have to address the evidence in cross-examination, sinceDaubert provides no reasonable grounds on which to exclude it. But the plaintiff is not doomed, and the evidence is not damning. The plaintiff should challenge the defense expert’s conclusions so that only those conclusions that are validly supported by the studies can be presented to the fact-finder.

4. Challenging Conclusions: If a glacier grows in Greenland, is climate change debunked?

A trial judge in a Daubert hearing may admit an expert’s testimony but restrict the expert from voicing his or her conclusions if those conclusions are not merited by the evidence.[146] Although Daubert focused on the scientific merits of theories and techniques rather than conclusions, the Supreme Court in General Electric Co. v. Joiner stated that a trial judge may consider the merits of an expert’s conclusions, and may exclude the conclusion if “there is simply too great an analytical gap between the data and the opinion proffered.”[147] One form of such a gap is where an expert has failed to account for obvious alternative explanations.[148] Should our hypothetical defendant attempt to vault that gap with the glacier studies, our hypothetical plaintiff should draw a line in the ice over what conclusions those studies can or cannot be said to support. Climate change skeptics have used these studies primarily to support two assertions. First, the studies have been used to support the proposition that “for every shrinking glacier there’s one that’s growing,” i.e., you don’t need to worry about sea levels rising. Second, the studies are given as evidence that the consensus model must be wrong. These studies do not in fact support either of these positions.

Skeptics get a number of benefits from the “for every shrinking glacier there’s one that’s growing” storyline. First, it seems to contradict concerns about sea level rise. Second, it’s an antidote to the frankly distressing visual evidence that the media frequently shows of receding glaciers in places like Alaska and Mount Kilimanjaro.[149] Third, it allows skeptics to push their meta-narrative that the media and the scientific establishment do not want you to know the truth about global warming. The problem with the “for every shrinking glacier” storyline, however, is that it is simply not an accurate statement about total world accumulation and loss of glacial ice. Although there is evidence that some glaciers are gaining mass, research suggests that substantially more ice is being lost from melting glaciers than is accumulating in the expanding glaciers.[150] The Johannessen and Davis papers never suggest that their results contradict the general trend of a net loss of ice; their focus is rather on understanding the overall dynamics of glaciers in these regions.[151] Moreover, the “for every shrinking glacier” storyline glosses over the fact that the location of glacial ice can be significant, particularly to communities that depend on glaciers for their water, such as in many parts of India.[152] An expert could testify accurately that the overall loss of ice in some glaciers is partially offset by the growth of glaciers in other regions, but any suggestion that the losses are canceled out should be excluded as unsupported by the evidence.

The second claim the skeptics advance with the glacier studies is the assertion that if glaciers are growing, the world cannot be warming, so the consensus model must be wrong. The problem with this claim is that it builds a paper tiger – it misstates the consensus model so that it can then disprove it. The consensus model does not suggest that temperatures will constantly rise everywhere in the world at the same rate. Climate is complicated, and GHG-forced global warming is a long-term process that interacts with the myriad other factors that make up climate in different regions.[153] Different rates of warming, or even cooling, in different areas at different times cannot disprove the consensus model; thus, the statement that “on average, the world is getting warmer,” is not inconsistent with a finding that one area has apparently gotten cooler in recent years, or that a certain set of glaciers have expanded. Thus, to say that studies showing expansion of some glaciers in Greenland and Antarctica disproves the consensus model is to misrepresent the consensus model, and to misrepresent the studies. Such misrepresentation would appear to be the kind of “analytical gap” referred to in Joiner.

While this argument might succeed in having such conclusions by the defense expert excluded, there is something unsatisfying about the defensive argument that “just because glaciers are growing does not mean the standard climate model is wrong.” After all, it would be hard to blame a fact-finder for thinking that growing glaciers might be inconsistent with claims of a warming planet. Fortunately for our plaintiff, thickening interior glaciers in Greenland and Antarctica are not just not inconsistent with the consensus model, they are actually consistent with it, and might be further evidence that global warming is happening.

As the Johannessen and Davis papers report, glaciers in the interiors of Greenland and Antarctica are getting thicker because these regions are getting more snow.[154] Climate change models have been predicting this result for decades.[155] The air over the interiors of Greenland and Antarctica is very cold and extremely dry; it is so dry that under ordinary conditions precipitation is rare, as in a desert. As the seas around these regions warm, however, the moisture level in the air increases, which leads to more precipitation, usually in the form of snow. As the snow accumulates in these interior regions, the ice-sheet thickens.[156] Curt Davis, the lead author of the Antarctica glacier study, said, “It’s been long predicted by climate models. This is the first observational evidence.”[157] This phenomenon of warmer water leading to thicker glaciers is good news, to a degree. For the present, it is apparently slowing down the rise of sea level. The models also predict, however, that at a certain point of warming the volume losses from melting will exceed the gains from snowfall, with the result that these interior glaciers, like those on the coast, will make a net contribution to rising sea levels.[158] Thus, while it would be valid to conclude from the glacier studies that sea level increases will be mitigated in the near term, the studies in no way support the assertion that the consensus model is incorrect.

If a defendant attempts to offer expert testimony regarding the Johannessen and Davis studies, the plaintiff should challenge any conclusion offered by the expert that interprets the evidence in an unsupported or prejudicial way. The plaintiff can make a strong argument that any assertions that growing glaciers cancel out contributions to sea level rise from melting glaciers, or that the evidence of glacial growth contradicts the consensus model, present “too great an analytical gap between the data and the opinion proffered.”[159] While this form of challenge will not exclude the presentation of the evidence itself, it will prevent the defendant from presenting the evidence in a scientifically unsupported way that could confuse the fact-finder about the most valid conclusions to draw from the evidence.

Part IV: Conclusion

This paper began with the question of whether climate change plaintiffs will be able to use Daubert challenges to exclude testimony by defense experts. I suggest that they will be able to do so. If climate change defendants put forth the same types of “experts” and scientific assertions that opponents of GHG regulations have embraced in the public debate over global warming, plaintiffs will be able to exclude or restrict the defendant’s expert testimony by employing the Federal Rules of Evidence in the four methods I have described: challenging the witness, challenging reliability, challenging relevance, and challenging conclusions. I propose three general observations about the significance these challenges could have.

First, use of Daubert challenges by plaintiffs could have a beneficial effect on the discussion of climate change science in the courtroom, and hopefully in the world at large. Daubert challenges brought by plaintiffs will not result in summary judgments, as they often do for defendants, but they will hopefully focus the courtroom debate on the actual scientific issues of climate change, as opposed to the smoke-and-mirrors evidence and conclusions that have so often prevailed in the public debate. A rigorous weighing of the evidence on both sides of the debate will show that the proponents of the consensus model have by far the stronger case.[160] While this may not necessarily result in courtroom victories for plaintiffs – the issues of specific causation and damages still loom large as obstacles to recovery – a rigorous debate in the courtroom will hopefully add rigor to the public debate on global warming. Proponents of GHG regulations may be able to point to the fact that their opponents’ evidence was not even allowed inside the courtroom door. The general public may take note of the cases and see how a court, with strict rules of evidence, sifts through the competing claims. As in many forms of impact litigation, the most significant effects of the lawsuit may happen entirely apart from the actual litigants in the case.

Second, the use of Daubert by climate change plaintiffs could provide a blueprint for Daubert challenges by plaintiffs in other contexts. While those who have complained loudest about “junk science” in the courtroom have focused on the evidence presented by plaintiffs,[161] there has been little movement in the courts to restrict the manipulation of scientific claims by corporate defendants. This is not because corporate defendants rely only on “sound science”; the examples of tobacco and asbestos litigation make abundantly clear that corporate defendants have extensively manipulated scientific claims in order to suit their legal purposes.[162] These defendants and those in other industries have sponsored research specifically to manufacture uncertainty about plaintiffs’ claims so that they can label those claims as “junk science.”[163] One way corporations can do this is to fund the research they want; substantial evidence suggests that corporations can tilt the odds that research will provide favorable results through means of a “funding effect.”[164] It is an unfortunate aspect of Daubert that it is poorly designed to weed out junky claims made by a party with the resources to dress them up in scientific clothes with tests, paid experts, and friendly publications. But if the justice system allows the Daubert standard to be no more than a tool of the party with the greater resources, then it allows litigants to make a mockery both of science and justice. If trial lawyers are able to use the scientifically hospitable terrain of climate change litigation to reclaim some Daubert territory from the hands of defendants, they may create precedents that will be valuable to other litigants in scientific disputes. They may also reinvigorateDaubert,not as a tool for the party with the greater resources, but as a lens for honing in on the answer that science and justice supports.

My third observation is that if the political debate on climate change treats the weaker scientific argument as the stronger, then there is something wrong with how the political debate deals with science. The official policies of the federal government over the last eight years have been precisely what we should expect if the scientific evidence suggested that climate change is not happening and will not happen. The federal government refused to join the Kyoto Protocol, it has failed to create a nationwide mandate or cap-and-trade program to reduce GHG emissions, and it has otherwise failed to take any step that could be expected to lead to meaningful reduction of GHG emissions.[165]This failure to act occurred in the face of powerful and unambiguous statements by the IPCC, the National Academy of Sciences, and other scientific organizations that the evidence strongly suggests that GHG emissions are warming the planet and will continue to do so.[166] What accounts for this disconnect between policy and scientific evidence? The range of factors that go into something as complicated as national environmental policy are mostly beyond the scope of this paper, but I will offer one suggestion. The political process is bound by nothing like the Federal Rules of Evidence, so bad science can carry just as much weight as good science in the political process. If a United States Senator in charge of the Senate committee with chief responsibility for the environment can point to a television weatherman as an expert on climate, or can invite a novelist to instruct the committee on climate science, something is wrong with the process. One solution might be for Congress to promulgate its own Congressional Rules of Evidence, modeled on the Federal Rules of Evidence, to sift through competing scientific or economic claims. Or, less drastically, the political actors could look to how the courts would evaluate scientific evidence, and then take this consideration into account before advancing experts or scientific claims in the political process. Spurring this kind of analysis could be one of the great ancillary benefits of climate change litigation.

The example of climate change litigation may also suggest something about judicial deference to the political branches in matters of scientific complexity.[167] If the political branches have evaluated the scientific claims on a topic as important and well-studied as climate change, and come to the conclusion that the skeptics have the better argument, or at least acted exactly as they would if that were the case, then perhaps the supposedly superior fact-finding abilities of Congress and the Executive are less superior than courts have been supposing. Perhaps the formal adversarial process of the judiciary, regulated by the Federal Rules of Evidence, can actually produce a more accurate statement about certain scientific claims than can the political branches, which have no such formal evidentiary rules and which are constantly swayed by political pressures to evaluate the scientific claims one way or another. Obviously, there are some strong legal and policy arguments in favor of judicial deference on matters of fact-finding, but the example of climate change does suggest that judicial deference may not always be merited.

As I hope these conclusions suggest, climate change litigation is an important legal development that could have substantial consequences both in other areas in the law and outside of the courtroom. Daubert challenges by climate change plaintiffs can play a key role in shaping those consequences.

[2]See Intergovernmental Panel on Climate Change, Climate Change 2007: The Physical Science Basis: Summary for Policymakers: Contribution of Working Group I to the Fourth Assessment 5 (2007) [hereinafter IPCC] (“[t]he understanding of anthropogenic warming and cooling influences on climate has improved since the Third Assessment Report (TAR), leading to very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming.”) See also National Academy of Sciences, Understanding and Responding to Climate Change: Highlights of National Academies Reports 2 (3d ed. 2008) [hereinafter NAS] (“Most scientists agree that warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere.”); American Association for the Advancement of Science, AAAS Board Statement on Climate Change, 1 (Dec. 9, 2006) (hereinafter AAAS) (“The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society.”).

[11] People of the State of California v. General Motors Corp., 2007 WL 2726871 at *16 (N.D. Cal.). Another high-profile public nuisance case that was dismissed on political question and standing grounds prior to any debate over scientific evidence was Comer v. Murphy Oil, U.S.A., No. 1:05-CV-00436 (S.D. Miss. Aug. 30, 2007) (dismissing nuisance claim brought by victims of Hurricane Katrina against oil and gas companies, alleging that the GHG emissions by those companies exacerbated hurricane damage).

[12]See Edward J. Larson, Summer for the Gods: The Scopes Trial and America’s Continuing Debate Over Science and Religion (1997) (describing the 1925 trial in Tennessee over the legality of teaching evolution in public schools). Although the Scopes trial is primarily remembered today for the fiery debate over evolution and creationism between Clarence Darrow and William Jennings Bryant, as popularized in the film Inherit the Wind (1960), in the actual trial the majority of expert testimony was excluded on relevance grounds.

[18] See David Hunter & James Salzman, Negligence in the Air: The Duty of Care in Climate Change Litigation, 155 U. Pa. L. Rev. 1741 (June 2007) (examining how climate change plaintiffs could establish a duty of care in negligence, products liability, and nuisance actions); Matthew F. Pawa & Benjamin A. Krass, Global Warming as a Public Nuisance: Connecticut v. American Electric Power, 16 Fordham Envtl. L. Rev. 407 (arguing that “global warming is indeed a public nuisance for which the defendants may be held liable as contributors.”); Christine Klein, The New Nuisance: An Antidote to Wetland Loss, Sprawl, and Global Warming, 48 B.C. L. Rev. 1155, 1220–33 (arguing for the use of public nuisance lawsuits as a catalyst for legislative action); Dan Mensher, Common Law on Ice: Using Federal Judge-made Nuisance Law to Address the Interstate Effects of Greenhouse Gas Emissions, 37 Envtl. L. 463 (Spring 2007) (arguing that in the absence of legislative and administrative action on GHGs federal common law remedies must be available).

[23] Joel Achenbach, The Tempest, Washington Post Magazine, May 28, 2006, at W08. Achenbach provides a fairly balanced journalistic take on the arguments advanced by climate change skeptics. Achenbach notes a fourth line of argument – if global warming is happening, there is nothing we can do about it – but this argument tends to be economic and political rather than scientific. For a more polemical statement of the skeptical position, see Christopher Horner, The Politically Incorrect Guide to Global Warming and Environmentalism (2007). Horner is a senior fellow with the Competitive Enterprise Institute, one of the most prominent skeptic think-tanks. The Competitive Enterprise Institute’s position on climate change is available at http://cei.org/issue/48.

[26] Fed. R. Evid. 702. From 1975 to 2000 Rule 702 provided, “If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.” Rule 702 was amended in 2000 to reflect the holding in Daubert.

[34]Id. at 594. The court’s statement appears to group error rate and control standards together, but it is probably preferable to view these as distinct criteria. See, e.g., Owens at 358 n.83 (“the separation of these two distinct factors clarifies analysis.”).

[60]Id. at 804 n.2 (“Certainly, nothing in the record as it now exists evinces either the reliability or validity of [the expert’s] testimony.”).

[61] Cook v. American S.S. Co. 53 F3d 733, 739–40 (6th Cir. 1995) (“[The expert]’s causation opinion, adorned as it was in the dress of scientific or technical expertise and fortified by the court’s later instruction to the jury calling it ‘expert opinion,’ was not expert testimony under Rule 702.”).

[67] Andrew Dessler, The ‘Inhofe 400’: Busting the ‘consensus busters’, Gristmill, Dec. 27, 2007http://gristmill.grist.org/story/2007/12/26/1971/6517 (initiating a series of critical profiles of the “Skeptic of the day”); Dan Shapley, Inhofe’s 400 Global Warming Deniers Debunked List of “Scientists” Includes Economists, Amateurs, TV Weathermen and Industry Hacks, The Daily Green, Jan. 11, 2008, available athttp://www.thedailygreen.com/environmental-news/latest/inhofe-global-warming-deniers-47011101 (asserting that, of the 400, 84 have taken money from the energy industry, 49 are retired, 44 are television weathermen, 20 are economists, and 70 have no apparent expertise in climate science); Joseph Romm, The cold truth about climate change, Salon.com, Feb. 7, 2008, available at http://www.salon.com/news/feature/2008/02/27/global_warming_deniers/ (“[T]he list is both padded and laughable, containing the opinions of TV weathermen, economists, a bunch of non-prominent scientists who aren’t climate experts, and, perhaps surprisingly, even a number of people who actually believe in the consensus.”)

[72]Id. (“My biggest argument against putting the primary blame on humans for climate change is that it completely takes God out of the picture. It must have slipped these people’s minds that God created the heavens and the earth and has control over what’s going on. (Dear Lord Jesus . . . did I just open a new pandora’s box?) Yeah, I said it. Do you honestly believe God would allow humans to destroy the earth He created?”). Allen’s position on this issue is criticized as scientifically (and perhaps theologically) unsound in the environmental website Gristmill. Andrew Dessler,The ‘Inhofe 400’ Skeptic of the Day, Gristmill, Dec. 30, 2007, http://gristmill.grist.org/story/2007/12/29/125741/46.

[75]See, e.g., Frazier v. Continental Oil Co., 568 F.2d 378, 383 (5th Cir. 1978) (allowing engineer to testify as to improper design of gas tank and venting system where witness was a member of the Mississippi Engineering Society, the National Society of Professional Engineers, and a fellow in the American Society of Civil Engineers).

[77] See generally Wilson v. City of Chicago, 6 F.3d 1233, 1238 (7th Cir. 1993) (“If the judge is not persuaded that a so-called expert has genuine knowledge that can be genuinely helpful to the jury, he should not let him testify.”).

[78] Berry v. City of Detroit, 25 F.3d 1342, 1351 (6th Cir. 1994) (“The issue with regard to expert testimony is not the qualifications of a witness in the abstract, but whether those qualifications provide a foundation for a witness to answer a specific question.”); Carroll v. Otis Elevator Co., 896 F.2d 210, 212 (7th Cir. 1990) (“Whether a witness is qualified as an expert can only be determined by comparing the area in which the witness has superior knowledge, skill, experience, or education with the subject matter of the witness’s testimony.”); Aloe Coal Co. v. Clark Equipment Co., 816 F.2d 110, 114 (3d Cir. 1987) (trial court erred in permitting witness to testify as to cause of tractor-shovel fire where he had no training as mechanic nor experience operating construction machinery but was merely a salesman who at times prepared equipment-damage estimates).

[79] Michael Crichton, State of Fear (2004). The novel ends with several pages of footnotes that purport to substantiate the hero’s scientific claims. In the preface, Crichton remarks that although the novel is a work of fiction, “Footnotes are real.”

[90] Colorado State University Department of Atmospheric Sciences, Faculty Profile, William M. Gray – Professor Emeritus, http://www.atmos.colostate.edu/dept/faculty/emeritus/gray.php. PDFs of many of Gray’s publications are available on the website of the Colorado State University Tropical Meteorology Project: http://typhoon.atmos.colostate.edu/Includes/Documents/Publications.html.

[91] A detailed portrait of Gray’s career and current stance on climate change is provided in Chris Mooney, Storm World: Hurricanes, Politics, and the Battle Over Global Warming (2007). A profile in the Washington Post Magazineidentified Gray as “The World’s Most Famous Hurricane Expert.” Joel Achenbach, The Tempest, Washington Post Magazine, May 28, 2006, at W08.

[93]Id.See also, William M. Gray, Viewpoint: Get off warming bandwagon, BBC News, November 16, 2000, available at http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2000/climate_change/1023334.stm. (“These small global temperature increases of the last 25 years and over the last century are likely natural changes that the globe has seen many times in the past. This small warming is likely a result of the natural alterations in global ocean currents which are driven by ocean salinity variations.”).

[98] William Gray, Statement of Dr. William Gray, U.S. Senate Committee on Environment and Public Works, Hearing Statements, September 28, 2005, http://epw.senate.gov/hearing_statements.cfm?id=246768. (“It is impossible to write computer code to represent such complexity and then realistically integrate hundreds of thousands of time steps into the future.”)

[99] Chikovsky v. Ortho Pharmaceutical Corp., 832 F. Supp 341 (S.D. Fla. 1993) (excluding physician’s testimony that the acne cream Retin A is a teratogen where the physician was not aware of any published article or treatise reporting that Retin A causes birth defects); United States v. Jones, 24 F.3d 1177 (9th Cir. 1994) (excluding criminal defense expert’s testimony based on a novel voice identification technique that had never been published or submitted to peer review).

[100] Joel Achenbach, The Tempest, Washington Post Magazine, May 28, 2006, at W08 (“[W]hen you press him on his theory of how thermohaline circulation has caused recent warming of the planet and will soon cause cooling, he concedes that he hasn’t published the idea in any peer-reviewed journal. He’s working on it, he says.”) While Gray has not published his theory in a peer-reviewed journal, he submitted a meeting paper outlining the theory at the 2006 Conference on Hurricanes and Tropical Meteorology. Gray’s theory and the scientific assertions in this paper are criticized in Gray and Muddy Thinking about Global Warming, RealClimate.org, April 26, 2006, http://www.realclimate.org/index.php/archives/2006/04/gray-on-agw/.

[101]See, e.g., Summers v. Missouri Pac. R.R., 897 F. Supp. 533 (E.D. Okla 1995) (excluding expert’s testimony regarding the plaintiff’s “multiple chemical sensitivity” where the theory of multiple chemical sensitivity has not been generally accepted by such representative medical organizations as the American Medical Association and the American College of Physicians).

[104] Empirical support for the positive feedback loop is provided in B. J. Soden et al., The Radiative Signature of Upper Tropospheric Moistening, 310 Science 841 (2005). The role of the positive feedback loop is described in Ray Pierrehumbert et al., On the Relative Humidity of the Earth’s Atmosphere, in The General Circulation (T. Schneider & A. Sobel, eds., 2005).

[105] Michael Shnayerson, A Convenient Untruth, Vanity Fair, May 2007, at 142. For an example of such a publication from the Cato Institute, see Patrick Michaels, Is the Sky Really Falling? A Review of Recent Global Warming Scare Stories, Cato Institute Policy Analysis no. 576, (August 23, 2006), available at http://www.cato.org/pub_display.php?pub_id=6622.

[106] Information about the Center for the Study of Carbon Dioxide and Global Change is available at their website at http://www.co2science.org/.

[107] Ross Gelbspan, Boiling Point: How Politicians, Big Oil and Coal, Journalists, and Activists have Fueled the Climate Crisis—And What We Can Do to Avert Disaster 54 (2004); ExxonSecrets.org, Factsheet: Center for the Study of Carbon Dioxide and Global Change, available at http://www.exxonsecrets.org/html/orgfactsheet.php?id=24.

[121]See Habecker v. Clark Equip. Co., 36 F.3d 278 (3rd Cir. 1994), cert den (U.S.) 115 S. Ct. 1313 (excluding expert’s testimony about his simulation of an accident where the simulation differed from the real accident in a number of important ways, such that conclusions could not validly be drawn about the real accident from the simulation); In re TMI Litig. Cases Consol. II., 910 F. Supp 200 (M.D. Pa. 1996) (excluding testimony regarding a scientifically reliable dendrometric study about effects of radiation on trees where the study could not assist jury in determining whether persons in affected area were exposed to radiation).

[123] In 1998 the Western Fuels Association, a coal cooperative, funded a nonprofit organization called The Greening Earth Society to promote the beneficial effects of heightened CO2. The Society opposed regulations in part because, “Our use of fossil fuels is helping give plants the extra CO2 they need to grow more lush and green worldwide.” Henry Noor, Energy Debate Heats Up, San Francisco Chronicle, August 14, 2000, at C-1. In 1991 the Western Fuels Association produced with Sherwood Idso a video titled The Greening of the Planet Earth, extolling the agricultural benefits of CO2 emissions. Ross Gelbspan, U.S. Coal Industry: Global Warming Is Good For Us, The Heat is Online,http://www.heatisonline.org/contentserver/objecthandlers/index.cfm?id=3046&method=full.

[127]See Fakri Bazzazz & John Grace, Plant Resource Allocation, 1 (1997) (“Plant biologists have long recognized that in order for a plant to complete its life cycle, it must function as a balanced system in terms of resource uptake and use.”).

[130] Jerry M. Melillo, Warm, Warm on the Range, 283 Science 183–84, 183 (January 8, 1999) (“increase in minimum temperature causes a distinct change in the mix of plants found in a prairie grassland in the Midwestern United States.”).

[140] The Competitive Enterprise Institute has reportedly received funding from the Alliance of Automobile Manufacturers, ExxonMobil, General Motors, the American Petroleum Institute, the American Plastics Council, and Arch Coal. Joel Achenbach, The Tempest, Washington Post Magazine, May 28, 2006, at W08.

[145] Sciencehas been publishing since 1880, it has the largest paid circulation of any peer-reviewed general science journal, and its peer-review process accepts less than eight percent of the papers submitted each year. http://www.sciencemag.org/help/about/about.dtl.

[153] MIT climatologist Kerry Emanuel has said, “There is this misperception that global change is a spatially uniform and smooth in time process. In fact that’s not true. There’s all kind of variability. You can find places in the world where the temperature has gone down for the past 50 years. When you’re looking for a signal in a very noisy record you do as much averaging as possible.” Quote in Joel Achenbach, The Tempest, Washington Post Magazine, May 28, 2006, at W08.

[156] Patrick Michaels, a climatologist at the University of Virginia and prominent climate change skeptic, concedes that the reported expansion of glaciers is due to climate change, but suggests that the phenomenon will mitigate rising sea levels. Patrick Michaels, Antarctic Ice: A Global Warming Snow Job?, Worldclimatereport.com, May 27, 2005 (“Climate scientists have long suspected that warming the oceans around a very cold continent is likely to dramatically increase snowfall. Consider Antarctica. It’s plenty chilly, dozens of degrees below freezing, and it’s surrounded by water. The warmer the water, the greater the evaporation from its surface, and, obviously, the more moisture it contributes to the local atmosphere.”).

[162]See, e.g., Michael Bowker, Fatal Deception: How Big Business Is Still Killing Us With Asbestos (2003) (describing the efforts by asbestos manufacturers to manufacture doubt about the role of asbestos in causing disease, and how their claims were exposed in the courtroom); Elisa K. Ong & Stanton A. Glantz, Constructing “Sound Science” and “Good Epidemiology”: Tobacco, Lawyers, and Public Relations Firms, 91 Am. J. Pub. Health 1749-57 (2001) (examining the use of the “sound science” defense by tobacco companies); Richard Kluger, Ashes to Ashes: America’s Hundred-Year Cigarette War, the Public Health, and the Unabashed Triumph of Philip Morris (1997) (documenting the tobacco industry’s manipulation of scientific claims about the health effects of tobacco); Lisa A. Bero et al., Publication Bias and Public Health Policy on Environmental Tobacco Smoke, 272 JAMA 133, 133-36 (1994) (studying sixty-five symposium articles and forty-nine peer-reviewed articles concerning tobacco smoke and finding sponsorship can influence results).

[163]See D. Michaels & C. Monforton, Manufacturing Uncertainty: Contested Science and the Protection of the Public’s Health and Environment, 95 Am. J. Public Health S1, S39–S48 (July 1, 2005) (describing the tactic of corporate defendants to promote studies that manufacture uncertainty in their opponents claims in order to label those claims as “junk science”); see also Thomas O. McGarity, Our Science is Sound Science and Their Science is Junk Science: Science-Based Strategies for Avoiding Accountability and Responsibility for Risk-Producing Products and Activities, 52 U. Kan. L. Rev. 897, 899 (“[M]any industrial targets of toxic tort lawsuits and federal regulations had been recasting self-interested appeals to economics as appeals to science for more than two decades.”).

[164] Sheldon Krimsky, The Funding Effect in Science and its Implications for the Judiciary, 13 J.L. & Pol’y 43 (2005). (examining the effects of academic funding and financial conflicts of interest on the integrity of scientific research, and the resulting consequences for courtroom testimony); Barry Meier, Contracts Keep Drug Research Out of Reach, N.Y. Times, Nov. 29, 2004, at A1 (describing how drug companies can suppress publication of unfavorable results); Marcia Angell, Is Academic Medicine for Sale?, 342 New Eng. J. Med. 1516 (May 18, 2000) (considering conflicts of interest inherent in the funding of pharmaceutical research).

[165] Loren R. Cass, The Failures of American and European Climate Policy: International Norms, Domestic Politics, and Unachievable Commitments 123–217 (2006); Ross Gelbspan, Boiling Point: How Politicians, Big Oil and Coal, Journalists, and Activists have Fueled the Climate Crisis—And What We Can Do to Avert Disaster 37–66 (2004).